The present invention relates to a cap and more particularly to a packaged additive cap adapted for use with containers for parenteral solutions and the like.
It is a common medical practice to introduce an additive, such as a prescribed medicament, to sterile medical solutions intended for intravenous feeding or for surgical irrigation. In such a case, the original protective outer closure of the solution container is removed, the piercable diaphragm of the inner closure is exposed, and the sterile additive solution is injected through the diaphragm to mix with the original liquid contents of the container. Since the additives are normally introduced into the containers at locations remote from those where the solutions are to be administered or used, and since a substantial time lapse may occur between introduction of an additive and use of the modified solution, sound medical practice requires that a new protective outer cap, commonly referred to as an additive cap, be placed over the inner closure immediately following introduction of the additive. Such an additive cap not only protects the inner closure against contamination prior to use or administration of the modified solution, but also indicates, usually by means of distinctive colorations of the additive cap, that the contents of the container have in fact been modified.
One problem in the use of sterile additive caps has been the risk of contaminating the inner surface portions thereof during removal of the caps from their wrappers or packages. Such a package has often taken the form of a dome-shaped thermoplastic bubble which receives the cap, the bubble being closed by a removable backing sheet. The entire cap within the bubble package is in a sterile condition prior to removal of the cap; however, users have sometimes experienced difficulty in removing such a cap from its package without contaminating that cap and, in particular, without touching and thereby contaminating the inner surfaces thereof. It should be noted that the outer surfaces of the bubble and backing sheet are presumed non-sterile. Consequently, finger contact with such surfaces, necessary for the purpose of opening the package in the first instance, would result in subsequent contamination of any surfaces of the cap later touched by the user while attempting to extract the cap from the opened package, even if the user took the extra precaution of putting on sterile gloves before undertaking such an operation.
Despite the need for improved packaging of sterile additive caps, bubble packages for such caps are still widely used and no completely effective substitute has heretofore been found. Packaging as commonly used in the medical field is generally illustrated in U.S. Pat. No. 3,630,346. The packaging heretofore used in various other fields is generally disclosed in U.S. Pat. Nos. 3,715,856, 3,192,091, and 3,394,869. The present invention represents a distinct improvement in the recognition of the problems associated with separately packaged sterile caps as well as the provision of a simple, improved structure of novel configuration which overcomes such problems in their entirety.